The Amiga was unique when it came out due to its custom sound and graphic chips that placed it beyond any existing home computer at the time (1985). Unfortunat

The Amiga was unique when it came out due to its custom sound and graphic chips that placed it beyond any existing home computer at the time (1985). Unfortunately, the hardware didn't change all that much and was slowly eclipsed first by graphics (VGA came out 1987 offering more colors) and then sound (SoundBlasters in the early 90s). The other issue was the operating system, which is really three pieces---Exec, DOS and Intuition. Exec is the kernel, written in 68000 assembly and appears as just another shared library to the system (neat design really). It's small (I was able to recreate over half of it in C in just a few hours) and would have been able to keep up as is until multiprocessor cores became popular, which would have required a somewhat major change (critical sections were handled by literally disabling task switching). It also has no notion of users (being a single user machine). DOS, the file system. This itself was a port of a portion of Tripos (written in BCPL) which only took two weeks to do (or four; it was a really short period of time). It's a bit quirky (due to it being written in BCPL) but it worked and given the nature of device drivers in the Amiga (a combination of shared library and a potential thread) it could easily support other file systems rather transparently. This is probably the least problematic aspect of the operating system to update for modern machines. And finally Intuition, the GUI. This was written in C, and unfortunately, was rather closely tied to the underlying hardware. Not only could you specify a new screen (different screen resolution and color depth) but access to the blitters (which were also used by the floppy disk drivers to decode the bit stream I kid you not) and even the raw video co-processor (a three-instruction CPU that could be used to reset the video registers at an almost arbitrary portion of the video scanning beam). Some of the upper layers of Intuition were fairly video independent but not enough of it to survive a major redesign of the video subsystem. You're pretty much right in that it was a "nice computer" (I found it really fun to program) but it didn't evolve all that much while on the market. Exec would need some work to work on today's multicore hardware and Intuition would have to be reworked from the ground up.